SU1689860A1 - Nonreversible counter of power - Google Patents

Abstract

The invention relates to electrical measuring equipment and can be used to measure electrical energy consumption in distribution grids. The aim of the invention is to improve accuracy when measuring in circuits with non-sinusoidal currents and voltages. The goal is achieved by introducing trigger 9, first and second switches 4 and 8, integrator 5, first and second threshold elements 6 and 7, and forming new connections. The integrator 5 integrates the signal, which is proportional to the electrical power of the network, in the forward or reverse direction, determined by the state of the switches 4 and 8, thereby generating pulses proportional to the power consumption. When the power direction changes in the network, the integration direction of the integrator 5 changes without switching the switches 4 and 8. As a result, the integrator 5 changes to a saturated state and the formation of pulses proportional to the power consumption is stopped. The device also contains measuring current transducers 1 and voltage 2, multiplier 3, pulse counter 10. 2 Il (L S

Description

o sooo

Fig 1

oh oh

The invention relates to electrical measuring equipment, namely, devices for measuring electricity, and can be used in electrical distribution networks.

The purpose of the invention is to improve the measurement accuracy in circuits with non-sinusoidal currents and voltages.

FIG. 1 is a block diagram of a non-reversible electric energy meter; Fig. 2 shows time diagrams of individual units of a non-reversible electric energy meter: a - voltage at the output of integrator 5; b - voltage at the output of the threshold element 6; c is the voltage at the output of the threshold element 7; d is the voltage at the output of the switch 8; g - voltage at the output of the trigger 10.

An irrespective electric energy meter contains current measuring transducers 1 and voltage 2, the outputs of which are connected to the input of multiplier 3, the direct and inverse outputs of which are connected to the inputs of the voltage-frequency converter, which contains the first switch 4, the output of which is connected to the input of the integrator 5 The output of which is connected to the inputs of the first and second threshold elements 6 and 7, the outputs of which are connected to the inputs of the second switch 8, the output of which, which is the output of the voltage converter, is often This is connected to the pulse counter 9 and the trigger 10, the output of which is connected to the control inputs of the first and second switches 4 and 8.

The counter works as follows. If there are 3 signals at the inputs of the multiplier, which are proportional to the current and voltage of the network, formed by measuring current transducers 1 and voltage 2, signals that are proportional to the power of a different sign are formed at its direct and inverse outputs. One of these signals through the first input of the first switch 4 is fed to the input of the integrator 5. When the output voltage of the integrator 5 reaches the pickup value of the first threshold element 6 (fig.2a) connected through the first input of the second switch 8 to the pulse counter 9 and the trigger 10, The first threshold element 6 generates a pulse, upon arrival of which to the input of the trigger 10, a pulse is formed at its output, switching the inputs of the first and second switches 4 and 8 (FIG. 2 e). The integrator 5 will integrate in the opposite direction (Fig. 2a) until the level at its output reaches the response value of the second threshold element 7, which through the second input of the second switch

8 connected to the inputs of the counter 9 pulses and trigger 10. When triggered, the second threshold element 7 (pigv) trigger 10

again generates a pulse that connects the direct output of multiplier 3 to the output of trigger 10. Integrator 5 changes the direction of integration, and the process of forming pulses at the output of the second

0 switch 8 (Fig.2G) and their account counter

The 9 pulses will continue in the above sequence.

The change in the direction of power flow in the network at time ti (Fig. 2a) calls the change in polarity of the signals at the output of multiplier 3 and the integration direction of integrator 5. At the same time, the same threshold element, for example, the first threshold element 6 (fig.2b) and forms a pulse at its output. However, this pulse does not go to the inputs of the pulse counter 9 and the trigger 10, because at the moment the output of the second threshold element 7 is connected to it and the trigger 5 rep 10 does not generate a pulse to switch the inputs of switches 4 and 8 (FIG. 2e).

In this case, the integrator 5 will enter the saturation state (Fig. 2a) and will remain there until the flow direction

0 power in the network will not be the same (time t2, figure 2). This will cause a reverse change in the signs of the signals at the outputs of the multiplier 3, the integrator 5 will change the direction of integration (Fig. 2a), and

5 the counter will enter the normal mode, continuing the formation of pulses at the output of the switch 8 and their counting.

In connection with the operation of the voltage-frequency converter of the proposed counter with alternating polarity signals having an offset that results from the multiplication of the current and voltage sinusoids, the device will have increased accuracy when operating in circuits with non-sinusoidal signals,

Claims (1)

5 since it will take into account the energy of all harmonic components of current and voltage. Claims of the invention A non-reversible electric energy meter containing measuring current and voltage transducers, a multiplier, a voltage-frequency converter, a pulse counter, the outputs of the current and voltage measuring transducers are connected to the corresponding 5th multiplier inputs, and the voltage converter output is connected to the input of the pulse counter, about that, h; oh, in order to improve measurement accuracy in circuits with non-sinusoidal currents and voltages, the voltage converter — the frequency contains the first and second switches, the integrator, the first and second threshold elements, the trigger, the input connected to the output of the second switch, and the output - to the control inputs of the first and second switches, and the inputs of the first comS the mutator is connected to the direct and inverse outputs of the multiplier, the output of the first switch is connected via an integrator to the inputs of the first and second threshold elements connected by outputs to the corresponding inputs of the second switch, the output of which is the output of the voltage-frequency converter.